7000SXT 1.05" vs 32mm distributor pipe

[Gary Slusser]

Very good explanation there. I don't worry all that much about hardness breakthrough for a big tub all that much because most of the time they fill that will soaps and scented oil and other herbal crap that is powerful enough to keep the water hardness from being much of a problem. Of course if someone else is showering at the same time they may be a little pissed off but again, I'm betting that situation won't come up often enough to be a problem. I also would reduce through the softener to 1-1/4

You are missing the importance of having used capacity that is not able to be regenerated with the salt dose being used, and how that affects the water quality until that resin is regenerated fully. That has to be done manually, no control valve/softener can do it automatically.

[midorix]

Man you sure are good with that California dreamin' PC speak and fortune telling.

Do you know the OP to be able to tell him regardless what he decides you know he'll be happy with it?

Maybe it's simply because you haven't sold to an end user in decades and won't be selling to him and you don't care if he gets it right or not. Maybe since you're into codes, you could tell him how the code says even a 2.5 cuft is not large enough for his 4.5 bathroom house and neither is the 1.25" valve or its distributor tube.

Hi Gary.

So do you think I'm taking the wrong path by going towards 2.0 cuft?
I know we have 4.5 bath but it will never be used all at once.
Probably the ideal is 1.5" distributor tube but again, many require 120K grain capacity to make this work (that's pretty much what I see as the minimum grain capacity in the market with one unit selling at 90K capacity).

I've also noticed that the 64K units comes in two different tank sizes 12x48 and 12x52. I'm sure the SFR is driven by resin volume but I also noticed that the SFR is quoted differently between these two tank sizes (I'm not sure why) unless SFR fluctuates really do change based on the tank size and type of resin used (mine is quoting 18.4 gpm with 1.05" distributor tube which means 32mm distributor tube should have higher SFR or maybe this is max rate and not constant). One I was planning to order is 12x52 tank size.

I've also received several feedback from different sellers and forum members like yourselves and majority were recommending sizes between 48K to 64K based on the stats noted above. However, I also know some sellers just use simple math by just factoring usage and not considering other factors like SFR and those considered such factors are recommending 64K (or someone has put it, correct sizing terminology is 2.0 cu ft since 64K can be achieved by adjusting the salt dosage using different resin volume).

I've read this article which gave pretty good insight on sizing: http://www.wcponline.com/pdf/0304%20...20Softners.pdf
I've also found this calculator to be most useful: http://www.apswater.com/Water_Softener_Calculator.asp

Hence based on all of these factors, it's pointing to 2.0 cuft (64K) sizing based on my very novice research.

I've also received some push back when I inquired about 2.5 cuft (80K) as they mentioned it's too large, not good for resin if regeneration cycle is too long (contrary to dittohead's pesonal experience), etc.

Trying to sift through all of these information (some probably not correct) has been a challenge, and I can see why many choose to go local dealer (like Kinetico) to get this done.

Again, I appreciate you, Tom, and dittohead's help and value all of your opinions (even though those opinions may be slightly different from each other).
I would then take those opinions and make my own decision and live with it...literally.

[Tom Sawyer]

From a code standpoint a 2.5 cu/ft is not big enough but then again, from a code stand point every single tankless water heater installed does not meet code either. However, code enforcement officials recognize that the chances of exceeding the capacity of either device on a regular basis is slim to none and because of the new energy and water conservation standards that have not yet been fully integrated into the codes, most will allow the installation.

[ditttohead]

Correct, I may not sell to end users anymore since that would be an obvious conflict of interest with my customers. I do however install 3-4 units a month for testing, prototypes, etc, in commercial, residential, and industrial applications. I only stopped doing regular field work a few years ago, where I was regularly installing 3-5 units a day residentially, or 2 units a day commercially. Not sure why my knowledge and experience would be diminished, bashed, or belittled by anyone on this board based on my lack of "selling to the end user". It has also been recommended to reduce the pipe size, a definite code violation in California, then followed up with a contradictory statement. Considering the OP understands the flow needs of his family, the lack of heavy water using items, and the OP also knows that with a 2 cu. ft. 7000SXT his estimated peak flow rate of 18 GPM, with a maximum recommended service flow of 15 GPM will meet his needs. The reason for the recommendation of a 2.5 Cu. Ft. system is to bump the maximum recommended service flow up to 18 GPM, which will match the est. peak flow rate. A 1-1/2" system, with a 2 cu. ft. tank will only yield a couple of extra gallons on the peak flow rate.

As to the true 1.5" units, the 2850s or similar valves can be installed on 2 cu. ft units and up to 20 cu. ft. While a 2 cu. ft. 1.5" system is not common, and it may be difficult to find online. See the attached picture below for specifications on all the common available sizes for the true 1.5" system. Again, for your application, it is probably not necessary, but it is the correct way to do it. For most 1-1/2" plumbed houses with 4 bathrooms, the 7000 on a slightly larger than normal tank is the most common design, or a 2850s as shown below. Figure approximately $1000 extra for the job completed due to the additional plumbing requirements of the 2850s. A 3 valve bypass, MIP connectors, t's, labor, and the higher system cost is what makes the 7000 so popular for large residential.

[Tom Sawyer]

You are missing the importance of having used capacity that is not able to be regenerated with the salt dose being used, and how that affects the water quality until that resin is regenerated fully. That has to be done manually, no control valve/softener can do it automatically.

Well I think you are "picking nits" here as usual considering all three of us are pretty much recommending the same set up. I have to base my thinking on what the OP is telling us and he is telling us that the chances of exceeding the SFR are slim to none. If he's worried about an inspector bitching about reducing the inlet and outlet than by all means, stick with the 1-1/2 connections, it's not like doing so will break the bank.

Nice to see you back in form though. Thought you might have been sick or something

[ditttohead]

From a code standpoint a 2.5 cu/ft is not big enough but then again, from a code stand point every single tankless water heater installed does not meet code either. However, code enforcement officials recognize that the chances of exceeding the capacity of either device on a regular basis is slim to none and because of the new energy and water conservation standards that have not yet been fully integrated into the codes, most will allow the installation.

Thanks, perfectly stated. The biggest problem with code and softeners is the minimum flow recommendations of a softener to prevent channelling. That is why we try to limit the systems to no more than 14" for residential, which would give an approximate minimum recommended flow rate of 3 GPM. If we were to do it perfectly, to code, it would require a system 14 design, with three controls, and the tanks would not be allowed to exceed 10" diameter. This would be correct, and to code, but not reasonable nor affordable. Even with 4 bathrooms, 20 GPM peak flow rates is more than adequate for more than 99% of the time. The worst thing that will happen is your softener will produce slightly more than a grain of hardness (hardly noticeable) if you exceed the maximum recommended flow rate. Honestly, do you forsee your family exceeding 15 GPM more than once or twice a year? Especially in states that require high efficiency plumbing fixtures. 2 GPM for showerheads, 1.5 GPM for faucets, 1.28 GPF for toilets, etc. have been the standard in California for many years.

I hope our information is helpful.

[midorix]

You guys are so cool and all of you are making sense! You don't know how much I appreciate that considering I've been muddling around trying to figure out which data or suggestion is correct or not.

Dittohead..you've "hit the nail on the head"..(pun intended).
Living in So. Cal for a very long time, and I've been preaching water conservation to my family regularly and I have all the high efficiency plumbing fixtures you described (I like to save environment and money).

All of you made it my choices clear now:

1. Pick 2.0 cuft 7000sxt - If I conclude I won't go over 15gpm SFR more than once or twice per year or don't mind if slight hardness comes through if I exceed the maximum flow rate (and I would have to run a full regeneration at 15lbs/ft3 of salt if this happens?)
2. Pick 2.5 cuft 7000sxt - If would go over 15gpm SFR more frequently but no more than 18gpm SFR
3. Pick 2.0 cuft 2850sxt - If I want to be compliance with the building code, can find a seller of such unit, and don't mind spending extra $1,000

Does this sound about right? (only thing not clear is the full regeneration requirement if I exceed the maximum flow rate. If it happens once, I need to do this or if it happens more frequently?)

[Gary Slusser]

Hi Gary.

So do you think I'm taking the wrong path by going towards 2.0 cuft?
I know we have 4.5 bath but it will never be used all at once.

Actually I think with your tub filling at 12.xx gpm, you may need larger than a 2.0 cuft.

And I know you nor anyone else can accurately predict that you'll never need a higher SFR than the 13 gpm of a 2.0' (either 12" x 48" or 12" x 52" [the correct size]).

I see ditto is now saying you'd exceed it maybe once or twice a year plus he uses a much higher constant SFR gpm for the 2 and 2.5' softeners than me or any resin manufacturer I know of. So since he is saying you'll exceed his much higher SFR gpm, and I use a much more realistic SFR gpm, you should need a larger softener than a 2.0 in a 12" x 52" tank with a gravel underbed.

The SFR we are talking about is a function of the resin and diameter of the tank, not the control valve although the control valve must be able to allow the flow rate without an excessive pressure loss.

Probably the ideal is 1.5" distributor tube but again, many require 120K grain capacity to make this work (that's pretty much what I see as the minimum grain capacity in the market with one unit selling at 90K capacity).

I've also noticed that the 64K units comes in two different tank sizes 12x48 and 12x52. I'm sure the SFR is driven by resin volume but I also noticed that the SFR is quoted differently between these two tank sizes (I'm not sure why) unless SFR fluctuates really do change based on the tank size and type of resin used (mine is quoting 18.4 gpm with 1.05" distributor tube which means 32mm distributor tube should have higher SFR or maybe this is max rate and not constant). One I was planning to order is 12x52 tank size.

The size of the distributor tube is not important (except to show how silly the code against reducing the connector fittings is). It will not reduce flow to where you could ever notice it. The same for a regular 1.05" DT or a 1" control valve. The dealers that limit the larger DT to 4.0' or larger softeners could use/sell one for a smaller softener if they wanted to.

The variations in SFR are due to various distributors using different figures and some dealers are confused and use the SFR of the control valve instead of the resin. I use slightly conservative figures but they compare favorably with resin manufacturers' figures because you only get to do this right when you buy the softener, there is no way to redo it once you have the softener installed without replacing the tank and buying more resin.

I've also received several feedback from different sellers and forum members like yourselves and majority were recommending sizes between 48K to 64K based on the stats noted above. However, I also know some sellers just use simple math by just factoring usage and not considering other factors like SFR and those considered such factors are recommending 64K (or someone has put it, correct sizing terminology is 2.0 cu ft since 64K can be achieved by adjusting the salt dosage using different resin volume).

Yes many dealers, plumbers, well drillers, etc. pay no attention to constant SFR of the softeners they sell.

If I were in still in business and you wanted to buy from me, I would not sell you a softener smaller than a 2.5 cuft.

No you don't get 64K using different resin volume, the volume is 2.0' and you vary the salt dosage lbs but, you get a max of 60K, not 64K.

[ditttohead]

Midorix, you are correct in what you said. Also, a softener in California must be programmed at no more than 4 pounds of salt per cu. ft. for efficiency standards. Most companies set their systems at 6-8 pounds in order to maintain higher water quality and for a multitude of other reasons, but Code is Code, so 4 pounds per cu. ft. is what I will stick with. The 2.5 Cu. Ft. system should cost nearly the same as a 2 cu. ft. system, and the flow benefits for your application easily justify it. Do not reduce the pipe size externally on the system either, code does have some allowances for internal plumbing of components to be reduced, this is due to velocity rates, dampaening affects, friction loss calculations, etc are all engineered into the equipment, the external plumbing, the part an inspector can see do not have allowances for pipe size reduction.

When the calculations were done for your plumbing, the engineer assumes no more than 8 FPS for desiging your plumbing size. This means your house could potentially use up to 44 gallons per minute if every item were used at the same time in the house. A softener that could provide a service flow rate of 44 gpm would be a 6 cubic foot 2850 on a 21" diameter tank. For obvious reasons, that would not be a reasonable system for your application, but it would technically meet all minimum flow requirements for code issues. At some point, common sense has to kick in and a reasonable compromise needs to be done. The 7000 will be available in a system 14 configuration in the future, this will make large residential applications that use small amounts of water the majority of the time a more properly designed and reasonably priced alternative to what is currently available.


As you can see by the chart, velocities shoud never exceed 9 FPS unless the system id designed, qualified, or engineered for these higher velocities. A riser tube inside of a resin tank is engineered and designed for considerably higher velocities. Water running through copper plumbing at higher velocites can cause considerable vibration, noise, wear, etc.

Hope this helps.

[lifespeed]

You've received some good advice here, but I'll chip in my two cents also, as a homeowner and user of the freely dispensed advice on this forum.

I have a Fleck 7000SXT 1.5 cu ft softener at 6 lbs/ft for 30K grain capacity to deal with 7 GPG hardness, preceeded by a 1.5 cu ft Fleck 7000 Centaur carbon filter to remove the chloramine from my municipal water 1" copper supply. Like yourself, I was concerned about not decreasing pipe diameter and maintaining a reasonable SFR for softening, as well as not inducing a pressure drop across the softener.

I did accomplish a low pressure drop across the filter and softener, but I do NOT have 1.5" service like yourself.


My family does not typically use 60 X 4 gallons per day, we are pretty conservative like many. at 240 GPD divided into 3857 gals capacity (10% reserve has been deducted) we should go 16 days between regenerations. It turns out to be much closer to 21 days between regeneration, the day override setting I have programmed into the valve. We usually use the alotted capacity before the timer forces a regen, so still very salt efficient.

Some say the regeneration is not frequent enough. However, I think this is only a concern if your water is dirty or has iron/manganese. My water does not, and I have not experienced any ill effects going 3 weeks between regens. I have to agree with Dittohead and others on this point. In fact, if you are to consider SFR as an important system specification, it would be impossible under most water conditions to size a system for 7 day regens unless you have very hard water, while still maintaining a 12+ GPM service flow rate.

As to your your 1.5" water service, I would be tempted if I were in your position to specify a valve with 1.5" internal ports. I may be biased having lived in a house that had inadequate plumbing before I repiped it to 1", but I really don't like high water velocities and undersized pipes. They are noisy, can cause water hammer, and fixtures interact with each other as they fight for restricted flow volumes. I would suggest it might be worthwhile to get the large 1.5" port 2850 valve and distributor tube to operate with minimal pressure drop in your plumbing, combined with the smaller tank suitable for 2.5 cu ft of resin. You may well end up going 2 - 3 weeks between regeneration, but this will be fine, and also salt and water efficient. Consider a carbon filter to remove chlorine. It is an added expense, but it is really nice not to have chlorine in the shower and your drinking water, and will prolong softener resin life. SST-60 resin is nice and the added expense is small, although not strictly necessary.

Finally, I prefer a reverse osmosis system under the kitchen sink for drinking and fridge water, fed by softened water. Salt is removed, and the taste is much better than the softened water, even though the whole house is carbon-filtered.

It sounds expensive, but ordering the proper equipment online is far more affordable than calling an expensive water guy.

Good luck with whatever you decide.

[Gary Slusser]

I have a Fleck 7000SXT 1.5 cu ft softener at 6 lbs/ft for 30K grain capacity to deal with 7 GPG hardness, preceeded by a 1.5 cu ft Fleck 7000 Centaur carbon filter to remove the chloramine from my municipal water 1" copper supply. Like yourself, I was concerned about not decreasing pipe diameter and maintaining a reasonable SFR for softening, as well as not inducing a pressure drop across the softener.

1.5 * 6 = 9 lbs of salt and that gets you 30,000 grains of capacity. 30,000/9 = a salt efficiency of 3333 grains/lb.

240 * 7 = 1680 grains used per day. 30,000/1680 = 17.85 days or, 1680 * 8 days = 13440 rounded to 14K. 14000/3333 = 4.2 lbs rounded to 5 lbs total per regeneration. And 14,000/7 = 2000 gallons. 2000/240= 8.3 days. 30,000/7= 4285 gallons. 4285/240 = 17.85 days.

Now none of that has anything to do with the constant SFR. That SFR is a function of the volume of resin and the tank diameter, in this case a 10" tank and 12 gpm.

In fact, if you are to consider SFR as an important system specification, it would be impossible under most water conditions to size a system for 7 day regens unless you have very hard water, while still maintaining a 12+ GPM service flow rate.

Not true, see above.

Some say the regeneration is not frequent enough. However, I think this is only a concern if your water is dirty or has iron/manganese. My water does not, and I have not experienced any ill effects going 3 weeks between regens. I have to agree with Dittohead and others on this point.

All waters have invisible 'dirt' in them, and 'city water' can be very dirty due the age and amount of sediment in the water distribution lines the water runs through from the treatment plant to your house.

[midorix]

Lifespeed, thanks for your input as well as everyone else.

I think you brought up a good point which I need to figure out is what would be my family's typical usage be.
Would we use the water softener as much as the this big house is capable of providing or will we just use partial?
I do believe everyone here who has been so helpful are providing the right advices based on limited information that I posted here.
This is where I contemplate, as like you, my family's water usage has been relatively conservative for past 8 years in this house (350 gallons per month including sprinklers is about right so actual water softener usage is probably in the 200s range). This is why I'm somewhat leaning towards 2.0 vs 2.5 ft3 even if it means I just have to be careful from SFR perspective.

In regards to 1.5" vs 1.25", I came to the conclusion that the distance that will be running though 1.25" distributor pipe is so short that impact would be minimal. At least that's what the physics/math will say. We'll see if it will be true in real life. And since I don't plan on selling the house anytime soon, I'm not as concerned about the building code as well (along as I'm not harming the environment or creating any hazardous situation).

I'm also not concerned about the drinking water as I have Culligan RO system that has been working great.

I post back here once decision is made and installation is complete.
I think everyone was nice enough to pitch in their thoughts but I need to make my own decision at the end.
This is a great forum and thank you so much to all of you.

[ditttohead]

You've received some good advice here, but I'll chip in my two cents also, as a homeowner and user of the freely dispensed advice on this forum.

I have a Fleck 7000SXT 1.5 cu ft softener at 6 lbs/ft for 30K grain capacity to deal with 7 GPG hardness, preceeded by a 1.5 cu ft Fleck 7000 Centaur carbon filter to remove the chloramine from my municipal water 1" copper supply. Like yourself, I was concerned about not decreasing pipe diameter and maintaining a reasonable SFR for softening, as well as not inducing a pressure drop across the softener.

I did accomplish a low pressure drop across the filter and softener, but I do NOT have 1.5" service like yourself.


My family does not typically use 60 X 4 gallons per day, we are pretty conservative like many. at 240 GPD divided into 3857 gals capacity (10% reserve has been deducted) we should go 16 days between regenerations. It turns out to be much closer to 21 days between regeneration, the day override setting I have programmed into the valve. We usually use the alotted capacity before the timer forces a regen, so still very salt efficient.

Some say the regeneration is not frequent enough. However, I think this is only a concern if your water is dirty or has iron/manganese. My water does not, and I have not experienced any ill effects going 3 weeks between regens. I have to agree with Dittohead and others on this point. In fact, if you are to consider SFR as an important system specification, it would be impossible under most water conditions to size a system for 7 day regens unless you have very hard water, while still maintaining a 12+ GPM service flow rate.

As to your your 1.5" water service, I would be tempted if I were in your position to specify a valve with 1.5" internal ports. I may be biased having lived in a house that had inadequate plumbing before I repiped it to 1", but I really don't like high water velocities and undersized pipes. They are noisy, can cause water hammer, and fixtures interact with each other as they fight for restricted flow volumes. I would suggest it might be worthwhile to get the large 1.5" port 2850 valve and distributor tube to operate with minimal pressure drop in your plumbing, combined with the smaller tank suitable for 2.5 cu ft of resin. You may well end up going 2 - 3 weeks between regeneration, but this will be fine, and also salt and water efficient. Consider a carbon filter to remove chlorine. It is an added expense, but it is really nice not to have chlorine in the shower and your drinking water, and will prolong softener resin life. SST-60 resin is nice and the added expense is small, although not strictly necessary.

Finally, I prefer a reverse osmosis system under the kitchen sink for drinking and fridge water, fed by softened water. Salt is removed, and the taste is much better than the softened water, even though the whole house is carbon-filtered.

It sounds expensive, but ordering the proper equipment online is far more affordable than calling an expensive water guy.

Good luck with whatever you decide.

Your point about regenerating is not understood by many. When it comes to regenerations "needing to be done every week", the math does not work in large houses, with few people, and low hardness. A house with a mega shower that needs 6 gpm, plus the rest of the fixtures, a flow rate of 15 GPM may be warranted, but if your hardness is only 5 grains, a softener that can handle those higher flow requiremnts, even regenerated at only 4 pounds per cubic foot may need go 20-40 days between regenerations. Even my house, with 6 people and 17 grains regenerates less than every 20 days and has done so for a decade. I programmed thousands of systems over my 25 years to regenerate in this fashion with no ill affects. As you said, iron, manganese, silt, etc, may justify the need for more frequent regenerations, but in general, for most municipal supplies, it is not necessary.

[Gary Slusser]

Folks....

That long between regenerations may be OK in southern CA but in most of the midwest and up and down the east coast I don't think it will work.

And only time, like a year or two, will tell. By that time if there is a problem, the resin will have to be replaced. And it certainly will not work on private well water anywhere.

[Tom Sawyer]

[QUOTE=Gary Slusser;351806]Folks....

That long between regenerations may be OK in southern CA but in most of the midwest and up and down the east coast I don't think it will work.

What would be different about Southern CA water as opposed to the rest of the country